AC not blowing cool air, Contractor said HVAC unit is perfectly fine and that it has to do with my smart thermostat (Ecobee 3)

So basically I changed out the filter on my HVAC unit (National Comfort Products, Model CPG41238-U23) and after I did that the AC stopped blowing out cold air. It was working completely fine until I changed the filter on the HVAC unit. The HVAC is relatively new and was installed August 2019. Had a contractor come and take a look and he checked every component of the HVAC unit and said that there is absolutely nothing wrong with the HVAC unit. He said that there is something wrong with my smart thermostat (Ecobee 3). He said that sometimes smart thermostats randomly turn off the system and that likely it will randomly come back on. He said to wait until Monday morning and see if it starts to work. Until then he is letting the HVAC unit run without a filter. He said if it starts to work then I can go ahead and put the filter back in. Does it make sense that my Ecobee 3 randomly is stopping my HVAC from blowing cool air? If so, is there anything I can do to troubleshoot the thermostat to get it to blow cool air again before monday morning? Thanks in advance for any help. I’ve attached a couple pictures of what the thermostat is saying and pictures of the wiring.

https://imgur.com/a/lVEbL2I